One thing that has puzzled those unfamiliar with the process of developing public examinations is that at least some of the leaked Key Skills trial questions later appeared in the real tests.

As one of the students who highlighted the leak put it: "It seems crazy to me to use the same test twice."

People have very, very poor memories

David Hargreaves, QCA

The head of the Qualifications and Curriculum Authority, David Hargreaves, said the process inevitably involved real questions being used.

They had to be tried and were then refined based on feedback from the trials.

When they were tried out, at a number of tests centres, efforts were made to see that the students who sat them were not likely to get them when they later sat the tests for real - but essentially the same pool of candidates had to be used.

"Wherever possible you try to introduce variations so that having done the trial is no particular advantage," he said.

Short memories

And in practice, even if students had seen questions before they tended not to remember them - especially with maths exams.

"People have very, very poor memories," he said.

"That's because nowadays they get much more help than in the past with practice papers, so they see a lot of them. They never remember."

He said this was less true with papers such as those in the Key Skills communication tests, where there was a strong narrative element.

Nevertheless, the whole test process is in jeopardy if trial papers are freely available.

"It was very helpful that the students told you about it," Mr Hargreaves said.

Did anyone realise?

Another question is whether anyone who saw the trial papers might have realised their significance before doing the real exams.

They were headed "Key Skills Trial October 2000" and bore the name of the Centre for Developing and Evaluating Lifelong Learning (CDELL) at the University of Nottingham.

But it might not have taken long for anyone reading up on Key Skills to realise their potential.

It was spelled out on the official Key Skills Support website by the head of the test development project, Peter Burke.

"CDELL has been working with experienced Key Skill practitioners, who have drafted the test papers which are now being trialled in centres across England, Wales and Northern Ireland," he wrote last autumn.

"The intention is that those questions which pass through the trialling phase successfully, will be available for use in the second assessment window for the phased implementation early in the summer term."

In due course they would go into a "key skills item bank" for exam boards to draw on.